Project Summary Alzheimer?s disease is a severe age-related chronic neurodegenerative disorder and the most common cause of dementia in elderly patients. The primary risk factor for AD is advancing age and there remains no cure for the symptoms or the disease. Several critical animal models have been established to evaluate neurological degradation and change associated with AD. The further development of non-human primate (NHP) models for AD and dementia symptoms offer the opportunity to bridge the gap between knowledge gained in rodent models and clinical testing in the elderly human population. The marmoset has proven to be a valuable resource and model for translational aging studies. Changes in metabolism, body mass, disease rate, and ambulation have been carefully characterized for the marmoset. Tools to evaluate cognition and neural function are under development and rapidly progressing. There is growing interest in developing noninvasive biomarkers to assess an individual?s risk of developing AD and AD-like dementia prior to the onset of cognitive decline. Both locomotor and olfactory function have been found to precede the development of cognitive symptomology in human AD patients. In order to increase the ability to assess the progression of neural decline associated with aging, including AD-like dementia symptoms in the marmoset as an AD model, it is necessary to expand the assessments available for use to evaluate early biomarkers of disease. Aim 1 will focus on assessing n=10 young and n=10 for behavioral and functional assays to assess gait speed using a footfall analysis system, limb strength using a force plate analysis system, muscle strength using surface EMG analysis, and gait stability using a balance ball analysis. Aim 2 will focus on the development of a behavioral test to assess olfactory sensitivity in marmosets. The development of these assessments and resources to expand tools of ambulation and olfactory function assessment will further the development of the marmoset as a model of early Alzheimer?s disease and other age-related diseases.